Accounting for the social gradient in diet quality and health

描述(申请人提供)：美国农业部营养政策和促进中心(CNPP)于2008年5月发布了全国食品价格数据库，首次使研究美国人口不同阶层的饮食质量和饮食成本之间的关系成为可能。这些价格是2001-2002年具有代表性的以人口为基础的国民健康和营养检查调查(NHANES)参与者所食用的食物的价格。NHANES的数据包括24小时饮食召回、体检和完成的详细人口统计和健康问卷。将食品价格向量(美元/100克)与国家饮食研究食品和营养数据库(FNDDS 1.0)联系起来，将能够在个人一级估计饮食的货币价值(美元/天和美元/2000千卡)，同时估计饮食与疾病相关性研究中常用的饮食暴露变量。能够将饮食成本与5,411名美国成年人(20岁)的NHANES饮食、人口、社会经济和生物标记物数据联系起来，将使我们能够罕见地第一次看到模型框架中将社会经济地位(SEP)和健康结果联系起来的中间机制。能量和营养摄入量将被用来计算每个受访者饮食的能量密度和营养密度。能量调整饮食成本的新衡量标准可能有助于解释观察到的肥胖症、II型糖尿病和代谢综合征的社会梯度。分析将确定饮食能量密度、饮食质量和能量调整后的饮食成本的SEP预测因素，并将阐明它们之间的关系，这是在美国成年人的大规模代表性样本中从未做过的事情。主要的假设是，饮食质量和成本将是负相关的；然而，这种关系的性质将因性别、种族/民族和SEP阶层而不同。第二系列分析将为感兴趣的亚群提供有关饮食质量和成本的描述性数据，包括美国人口中的高危和脆弱亚群，包括接受食品援助的人或患有慢性病的个人。在横断面研究的范围内，分析将探索饮食质量指标、饮食成本和健康结果之间的关系，包括测量的体重指数(BMI)、炎症的生物标志物、代谢综合征的个别组成部分(例如糖尿病、腹型肥胖、血脂异常、高血压、胰岛素抵抗、血栓形成和炎症)、代谢综合征和糖尿病。其中许多都与饮食中的特定成分有关。假设是，一旦能量调整的饮食成本被包括在模型中，饮食成分和健康之间的一些观察到的关联将被减弱。拟议中的研究提供了一个独特的第一眼，了解美国健康饮食和不健康饮食的成本，以及食品定价对健康的影响。 公共卫生相关性： 这项研究的目的是评估不同社会经济和人口特征群体的饮食成本和质量之间的关系。这项研究是由关于国家食品价格的新数据实现的，这些数据将与基于人群的饮食摄入量调查合并。这项工作解决了营养饮食的经济障碍，从而为研究健康方面的社会经济差距提供了至关重要的部分。这项研究的长期目标是建立一种新的方法来估计饮食成本，该方法直接与营养摄入量的估计相联系。这一方法将使研究人员能够将食品成本作为影响个人和大量人群饮食行为的一个因素进行评估。

DESCRIPTION (provided by applicant): The study of the relation between diet quality and diet cost among different strata of the US population has been made possible, for the first time, by the release of the national food price database by the USDA Center for Nutrition Policy and Promotion (CNPP) in May 2008. The prices were for foods consumed by the participants in the representative population-based 2001-2002 National Health and Nutrition Examination Survey (NHANES). The NHANES data include a 24-hour dietary recall, a medical examination and completed detailed demographic and health questionnaires. Linking the food price vector ($/100g) with the national Food and Nutrient Database for Dietary Studies (FNDDS 1.0) will allow for the estimation of the monetary value of the diet ($/day and $/2000kcal) at the individual-level, in parallel with the estimation of dietary exposure variables commonly used in studies of diet-disease associations. Being able to link diet costs with the NHANES dietary, demographic, socioeconomic and biomarker data for 5,411 US adults (agee20) will permit a rare first look at the intermediate mechanisms in the model framework that links socioeconomic position (SEP) and health outcomes. Energy and nutrient intakes will be used to calculate energy density and nutrient density of each respondent's diet. The new measure of energy-adjusted diet cost may help explain the observed social gradient in obesity, type II diabetes and the metabolic syndrome. Analyses will identify SEP predictors of dietary energy density, diet quality and energy-adjusted diet cost and will elucidate the relations among them, something that has never been done in a large-scale representative sample of US adults. The primary hypothesis is that diet quality and cost will be inversely linked; however the nature of that relation will differ by gender, race/ethnicity and SEP strata. The second series of analyses will provide descriptive data on diet quality and cost for subgroups of interest, including high-risk and vulnerable subgroups of the US population, including food assistance recipients or individuals with established chronic disease. Within the limitations of a cross-sectional study, analyses will explore the relation between diet quality measures, diet cost and health outcomes, including measured body mass index (BMI), biomarkers of inflammation, individual components of the metabolic syndrome (e.g., diabetes, abdominal obesity, dyslipidemia, high blood pressure, insulin resistance, prothrombosis and inflammation), the metabolic syndrome and diabetes. Many of those have been linked to specific components of the diet. The hypothesis is that some of the observed associations between dietary components and health will be attenuated once energy-adjusted diet costs are included in the model. The proposed studies offer a unique first look at the cost of healthful and unhealthful diets in the US and the consequences of food pricing on health. PUBLIC HEALTH RELEVANCE: The purpose of this research is to assess the relationship between the cost and quality of diets consumed by groups differing in socioeconomic and demographic characteristics. The study is made possible by new data on national food prices that will be merged with a population-based dietary intake survey. This work addresses economic barriers to nutritious diets and thus provides a vital part of the research on socio-economic disparities in health. The long term goal of this research is to establish a new approach to estimating diet cost that links directly to estimates of nutrient intake. The approach will allow investigators to assess food cost as a factor influencing the dietary behaviors of individuals and large populations.